1. Field of the Invention
The present invention relates to a recording material feeding apparatus configured to detect a remaining amount of recording materials on a stacking unit, and an image forming apparatus.
2. Description of the Related Art
Conventionally, as a stacker portion holding recording materials on which an image is to be formed, for example, a sheet cassette or a sheet feed deck is provided in an image forming apparatus. For the stacker portion, a configuration including a plurality of sensors for detecting whether recording materials exist and a stacking amount thereof has been known.
Japanese Patent Application Laid-Open No. 2000-153936 discusses a technique for detecting whether or not recording materials exist in the stacker portion using an optical sensor and a flag with different transmittances.
Although the detection sensor can detect whether the recording materials exist and the stacking amount thereof by only one sensor using a flag with different transmittances as discussed in the Japanese Patent Application Laid-Open No. 2000-153936, it is difficult to detect a difference in transmittance of the flag accurately. Further, producing such a flag having a plurality of transmittances leads to increase in cost.